1. Field of the Invention
The present invention relates to a thermal processing apparatus, a thermal processing method for performing a thermal processing to a substrate, and a substrate processing apparatus using the thermal processing apparatus.
2. Description of the Background Art
Conventionally, a thermal processor for subjecting a substrate to a thermal processing is mounted in a substrate processing apparatus including a semiconductor processing apparatus. The thermal processor includes a heating unit called a hot plate in which temperature is increased to a predetermined temperature, and a cooling unit called a cool plate in which temperature is decreased to a predetermined temperature.
Normally, a substrate after a heat processing is subjected to a cooling processing for cooling to a predetermined temperature. On the other hand, a substrate after resist-coated and developed is subjected to a heat processing for heating to a predetermined temperature. These cooling and heat processings require certain cooling and heating times, which are regarded very important in the formation of a substrate.
The number of thermal processors to be mounted in the substrate processing apparatus is determined depending on the balance of the processing capabilities of a resist coater, developer, and the like. The number of the thermal processors to be mounted varies correspondingly, although a plurality of thermal processors are normally mounted in one substrate mounting apparatus. In the case where the plurality of thermal processors are mounted in one substrate processing apparatus, disturbances due to the influence of heat from other processors and the like must be suppressed. However, because of the limitation for the layout of installation space or peripheral processors, it is difficult to arrange the plurality of thermal processors in a distributed manner; therefore, the plurality of thermal processors are required to be housed in a special shelf called a bake box. In the bake box where a large number of thermal processors are mounted, however, temperature adjustment for the heat cannot be efficiently performed due to the heat transfer among the thermal processors.
Further, a heated substrate after the heat processing is transported by a hand, which leads to accumulation of heat in the hand from the heated substrate. In one technique, a water duct and the like were provided around the hand for cooling. This technique, however, requires a large working space, in which the number of thermal processors to be mounted varies depending on the structure of the substrate processing apparatus, thus resulting in a problem of the cost.
Japanese Patent Laid-Open No.3240383 discloses a thermal processing apparatus which enables reduced heat/cooling processing times for an object to be processed, while maintaining the evenness of the in-plane temperature distribution of the object and improving product yields.
According to this thermal processing apparatus, there is provided a first transport means for transporting a plate-shaped object to be processed between a thermal processor and a resist processor, and additionally a second transport means for transporting the object between predetermined processors in the thermal processor, so that the object which has been subjected to a heat processing by a heating unit is received by the second transport means with a cooling temperature adjustment function which cools the object to a predetermined temperature, to transfer the object to a cooling section.
Therefore, with the thermal processing apparatus to Japanese Patent Laid-Open No.3240383, the object which has been subjected to the heat processing can be quickly transported to the cooling section, which may result in reduced influence of heat on the object, and also improved throughput. Here, the second transport means comprises the cooling temperature adjustment function, which allows the object being transported to undergo the cooling processing, thereby further improving the throughput.
In the thermal processing apparatus described in Japanese Patent Laid-Open No.3240383, however, because of the cooling temperature adjustment function provided to the second transport means, a water-cooled pipe and the like provided in the cooling temperature adjustment function are caused to slide as the second transport means moves. The durability of the water-cooled pipe and particles derived from the sliding water-cooled pipe have resulted in a big problem.